A bezoimidazole-based highly selective and low-background fluorescent sensor for Zn2+

In this article, a new benzoimidazole based Zn2+ fluorescence sensor DABI has been prepared. The sensor displays a rapid and a linear response to Zn2+ with a red-shifted 100-fold turn-on signal from the dark background. The presence of other metal ions especially Cd2+ does not interfere with its Zn2+ response. Molecular modeling study suggests that the Zn2+-induced red shift of emission and fluorescence turn-on of DABI could be correlated to the coplanation of two aryl planes of 2-aryl substituted benzoimidazole. (C) 2011 Elsevier B.V. All rights reserved.